Add API to easily pause target and wait for it to be ready

[jonahgraham]

There are a couple of places in the code where we wait for target to be suspended after issuing pause to ensure that we are operating on a suspended target. However those current places (such as use of waitPauseNeeded) are not very conducive for new places, such as what is needed by #292

This is an API feature request to add such support in a generic manner.